This invention generally relates to locks, and, more particularly, to tubular key actuated cam locks. Locks generally are subject to extensive efforts to defeat their defenses. A lock""s design and the materials used to manufacture the lock determine the lock""s strength and resistance to tampering. Tubular keyed cam locks provide additional security due the fact that the circular key is more difficult to pick than conventional tumbler locks. However, conventional tubular key-actuated cam locks use a diecast spindle or brass spindle protruding from the back of the cam lock to affix the rotatable cam to the cam mechanism. Such an arrangement can be defeated by applying enough pressure to the front or back of the lock to break the spindle, thereby prying off the lock.
Exemplary locks are disclosed in U.S. Pat. Nos. 4,006,616; 4,070,844; 4,099,398; 4,208,894; 4,425,770; 4,648,483; 4,674,777; 4,715,201; 4,830,168; 5,038,589; 5,152,161; 5,199,285; 5,251,467; 5,265,455; 5,678,438; 5,724,840; and 5,868,060. All of these devices have a number of drawbacks and, as such, provide limited security. It is an object of the present invention to solve the problems enumerated above.
The present invention provides a tubular keyed cam lock. The tubular cam lock has a rear screw attachment to the back end of the cam lock which affixes the cam to the back of the lock. As disclosed herein, the lock includes a plug body rotatably mounted inside a lock housing. The lock housing includes a plug cap with an opening permitting the entry of the key. The plug body has a key entering end and a cam actuating end, and a plurality of spring biased pin tumblers engaging the key when the key is inserted into the plug body. A rear screw attachment affixes the cam to the plug body. The lock housing has at least one limit stop disposed thereon.
It is the primary object of the present invention to increase the level of security associated with the use of tubular keyed cam locks in keyed applications, and to thereby reduce the unauthorized access to items secured by tubular keyed cam locks in conditions prone to tampering.
It is an additional object of the present invention to provide a tubular keyed cam lock which can be manufactured using existing techniques and machinery which has increased security.
The objects and features of the present invention, other than those specifically set forth above, will become apparent in the detailed description of the invention and drawings set forth below.